Jim DeMint and Marco Rubio, in Sync and on the Road in South Carolina

To hear South Carolina Sen. Jim DeMint tell it, it started with a conversation about a week after Marco Rubio, a former speaker of the Florida House, announced his challenge to popular Gov. Charlie Crist in that state's GOP Senate primary. Back in May, it was "David and Goliath," DeMint said recently. "I like that kind of courage."

DeMint said he was impressed by the "heartfelt" passion of the conservative Cuban-American candidate who "grew up with parents who lost their country." As Florida's August primary approaches, DeMint's early support for the man he said is "not the status-quo" Republican looks like a smart move. A Public Policy Polling survey, conducted March 5-8, has David leading Goliath, 60 percent to 28 percent, with 12 percent undecided. The Republican Senatorial Campaign Committee, an early Crist backer, has backed off, announcing it will spend no money on his behalf.

On Monday, they made three South Carolina stops on their "The Comeback Begins" tour, starting the day in Charleston and ending it in Greenville. I caught up with the two like-minded politicians at the second stop, a barbecue lunch in Columbia. I didn't get a chance to speak with Rubio or hear either speak at the event, which was closed to the press. About 100 people attended, according to DeMint's campaign spokesman, Ian Headley. (It cost from $35 for one attendee up to the $2,400 host level, which included lunch, a place in the photo line and recognition.)

But DeMint stepped outside for a few minutes, with a relaxed smile on his face and a "Marco 2010" pin on his lapel. His own profile has risen since his early opposition to President Obama. Last July, he predicted health care would be the president's "Waterloo," and when I asked about that on Monday, he told me: "I don't back off of it at all. It's true. This is a critical week for us, because it's important we stop the health care bill. If not, there's a wave of big government agenda items right behind it that are going to be harder to stop."

DeMint's quotable hard-line views have eclipsed what some in South Carolina see as the too conciliatory demeanor of the state's other senator, fellow Republican Lindsey Graham, whom I've heard disrespected by supporters of Rep. Joe ("You lie") Wilson at a rally, at Graham's joint town hall meeting with Sen. John McCain at the Citadel, and by Glenn Beck at a South Carolina book-signing. (Some will never forgive Graham his vote to confirm Supreme Court Justice Sonia Sotomayor.)

DeMint must feel comfortable enough in his own re-election race to share the spotlight with Rubio, whose campaign has benefited from more than $340,000 from DeMint's Senate Conservatives Fund. "If we can get Marco Rubio in Washington, he'll help us reshape the Republican Party," DeMint said.

A vocal fan of the Tea Party movement, he said the GOP needs to "embrace what's going on in our country because there's nothing small about it."

"This is a group out there that is saying exactly what we say we're believing," DeMint said. Of Republicans who are "stiff-arming" the Tea Party movement, "I just think they're out of touch." If the GOP doesn't respond, he said, "You'll see a third party."

"We can rebuild a strong majority and a majority that will actually do what we say we're going to do."

Mary Black, 58, has been a DeMint fan for a long time, even though she can't vote for him. She traveled from Statesville, N.C., to hear him and "up-and-comer" Rubio. Black, who, like everyone I spoke with, favors what she called a return to "the fundamentals of the Constitution," said she is "praying for our country every day."

"Everybody in health care knows our health care system needs work," said Hilda Barnwell, 62, a Columbia respiratory therapist. "Health issues can devastate a family." But she favors tort reform as a solution.

An Aiken, S.C., couple – "just say Debra and Dale" – said it's about taking the country back from the politicians. "They forget who sent them there in the first place," Debra said. And what do they think about Obama? "I don't think you can print it," Dale said.

Click play below to watch the Demint and Rubio's "The Comeback Begins" virtual town hall: